User profile for user: johnpmichaels
johnpmichaels Author
User level: Level 1
4 points

Cannot stop Time Machine

Drive for Time Machine backups is corrupted and I need to reformat it. I try to erase with disk utility, but file system can't be unmounted since there are still processes using the drive. I can't get Time Machine (or whatever other processes are using it) stopped long enough to get the drive unmounted. Error message from disk utility shows PID for offending process, but when I look for it, process is gone. Time Machine appears to keep restarting itself. Running Monterey 12.7.6 on 16G M1 Mini. External drive is 4TB OWC STX HDD.

TIA

Mac mini, macOS 12.7

Posted on May 2, 2025 02:00 PM

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User profile for user: D.I. Johnson
D.I. Johnson
User level: Level 7
30,971 points

Posted on May 2, 2025 02:17 PM

1) - Quit all running apps and shut down the Mac. If necessary, you can shut down by pressing and holding the power button until the computer shuts off.


2) - Disconnect the external drive and reboot the Mac. open System Settings > Time Machine > Options... and select "Manually" for the backup frequency.


3) - Reconnect the external drive, launch Disk Utility and erase the drive. Use GUID scheme w APFS format. After it's been reformatted, run DU First Aid on the volume, container and drive device in that order.


4) - Open Time Machine settings again, add the drive for backups if you've changed the drive name, then select your preference for backup frequency.


If the drive is healthy then you should be good to go.

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User profile for user: D.I. Johnson
D.I. Johnson
User level: Level 7
30,971 points

May 2, 2025 02:17 PM in response to johnpmichaels

1) - Quit all running apps and shut down the Mac. If necessary, you can shut down by pressing and holding the power button until the computer shuts off.


2) - Disconnect the external drive and reboot the Mac. open System Settings > Time Machine > Options... and select "Manually" for the backup frequency.


3) - Reconnect the external drive, launch Disk Utility and erase the drive. Use GUID scheme w APFS format. After it's been reformatted, run DU First Aid on the volume, container and drive device in that order.


4) - Open Time Machine settings again, add the drive for backups if you've changed the drive name, then select your preference for backup frequency.


If the drive is healthy then you should be good to go.

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Cannot stop Time Machine

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